EP3565983A1

EP3565983A1 - Synchronized free-wheel roller

Info

Publication number: EP3565983A1
Application number: EP18701782.7A
Authority: EP
Inventors: Vianney Rabhi
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-01-03
Filing date: 2018-01-03
Publication date: 2019-11-13
Anticipated expiration: 2038-01-03
Also published as: JP6955567B2; EP3565983B1; FR3061524A1; KR20190099294A; CN110199130B; KR102514722B1; CN110199130A; ES2874806T3; FR3061524B1; AU2018206286B2; WO2018127657A1; JP2020504270A; AU2018206286A1; CA3048881A1

Abstract

The invention relates to a synchronized free-wheel roller (1) comprising a central body (2) having an outer cylindrical rolling surface (3) intended to roll between two raceways bordered by synchronizer racks or synchronizer rings, each end (9) of the body (2) having a smooth shaft (10) about which a synchronizer pinion (8) can rotate freely, said shaft (10) including axial pinion-stop means (12) that prevent the pinion (8) from leaving the shaft (10), while axial roller-guiding means (13) bear on the central body (2) and on the raceways in order to maintain the outer cylindrical rolling surface (3) approximately centred on the raceways.

Description

SYNCHRONIZED ROLLER WITH FREE WHEELS

The present invention relates to a synchronized roller with freewheels co-operating mainly with four racks and two flat rolling tracks, or with two outer rings which border an inner annular raceway, and two inner rings which border an annular raceway. outer diameter of which is greater than that of the inner annular raceway.

Various applications are known in which synchronized rollers are used. For example, the tangential arm antifriction roller as described in the patent relating to a fixed or variable displacement hydraulic motor-pump published under No. FR 3,001,774 and belonging to the applicant, is in itself a synchronized roller.

In the same said patent No. FR 3 001 774, it is noted that the central rotor bearing of the hydraulic motor-pump may comprise central rotor bearing rollers while the peripheral rotor bearing of said motor-pump may comprise rollers of peripheral rotor bearing. Said rollers are also, and by nature, synchronized rolls.

According to this latter application, it is noted that said rollers can roll simultaneously on an inner bearing track which forms an inner annular raceway, and on an outer bearing race which forms an outer annular raceway.

The advantage of this configuration using synchronized rollers is that said rollers are constantly equidistant from each other by means of roller gears which they comprise at each of their two ends, said gears each cooperating on the one hand, with an inner crown, and on the other hand, with an outer crown.

The rolling bearings that result from said configuration do not require a ball or roller cage as comprise the ball or roller bearings ordinarily used in many mechanical devices. This is advantageous in that said cage is both less precise and less durable than synchronized rolls, and in that it regularly collides with the balls or the rollers which it encloses, which generates friction losses at the same time. level of its contact with said balls or said rollers.

In addition, it is noted in the patent No. FR 3 001 774 that in meshing with the inner and outer rings with which they cooperate, the roller gears impose on the bearing rollers a trajectory well perpendicular to the axis of rotation of the central rotor with respect to the central rotor bearing, and perpendicular to the axis of the peripheral rotor with respect to the peripheral rotor bearing. Among the claimed advantages for said rollers in the patent No. FR 3,001,774, it is noted that these can be of large diameter so that even if they are subjected to a very high load, the pressure of Hertz they exert on the inner track and on the outer track with which they cooperate may remain within the mechanical strength limits of the materials usually used by those skilled in the art to make the rolling bearings.

In addition, this particular design gives said rollers a maximum rotational speed which remains acceptable despite the large diameter of the rotor bearings that includes the motor-pump.

Thus, the synchronized roller bearings as described in the patent No. FR 3 001 774 can both be of large diameter, withstand heavy loads and high radial forces, and rotate at high speed, this combination of functional conditions being little or not accessible rolling bearings usually implemented by those skilled in the art.

In addition, it is easy to deduce from this particular configuration that said bearings can offer a high efficiency thanks in particular to the absence of cage as previously mentioned, but also thanks to the absence of need to generate a little friction between the rollers and the inner and outer tracks with which they cooperate to force said rollers to follow a trajectory as perpendicular as possible to the axis of rotation of the bearing which they constitute one of the components. In fact, according to the synchronized roller bearings as described in the patent No. FR 3 001 774, the orientation of said rollers is ensured by the gear system that form the roller gears with the inner and outer rings with which they cooperate. Among other applications in which synchronized rollers are used, there is the mechanical transmission device for variable displacement motor object of patent FR 2,786,530 belonging to the applicant.

Said patent discloses a rolling guide device consisting of two synchronized rollers which provide frictionless guidance of two half-racks on an engine block.

Note that according to a variant proposed by said patent No. FR 2 786 530, the synchronized rollers may consist of a hollow cylindrical sleeve longitudinally traversed by an axis at both ends of which are fixed toothed wheels made integral in rotation with said axis by splines. Note that in this case, a free space is left between said sleeve and said axis, said space receiving an elastic connection. Patent No. FR 2 827 634 also belonging to the applicant relates to improvements made to the mechanical transmission devices for variable displacement motor. Said patent also provides a synchronized roller consisting of a cylindrical body having at each of its ends gears, and a guide groove provided between the gears. This particular configuration is also found in the patent No. 2 956 452 also belonging to the applicant, and which relates to a piston compressor double acting guided by a roller and driven by a toothed wheel and racks. In said patent No. 2 956 452, it is noted that the double-acting piston compressor comprises a transmission member which has a rolling surface on which can roll a guide roller whose ends have small toothed wheels.

Like the synchronized roller described in patent FR 2 827 634, the guide roller provided for in Patent No. 2 956 452 cooperates with rolling surfaces and racks.

The synchronized rollers as described in patents FR FR 3 001 774, FR 2 786 530, FR 2 827 634 and 2 956 452 all have the particularity of having a cylindrical rolling surface which constitutes the body of said rollers, the diameter of said surface being close to or even identical to that of the pitch circle of the toothed wheels that comprise said rollers at their ends.

In any event, the devices having no cylindrical rolling surface such as that proposed for example patent No. US 499,847 of June 20, 1893 relating to a rolling car, are foreign to the subject treated in the present patent application. This remark also applies to patent No. GB 608,153 of February 15, 1946 relating to improvements for crank mechanism.

In addition to having a rolling cylindrical surface ensuring minimal friction displacement, the interest of the synchronized rollers as just described is that they always maintain the same speed of movement relative to the racks or crowns with which they cooperate or well - depending on the mechanism in question, they always maintain the same position relative to said racks or said crowns. Note that the synchronized rollers are mainly retained for particularly loaded applications in which said rollers are subjected to a high radial compressive force. In most cases, this radial compression excludes any recourse to a hollow cylindrical sleeve as proposed in Patent No. FR 2 786 530, said sleeve being insufficiently rigid and being too resistant to crushing. In addition, said compression poses various implementation problems to which the synchronized freewheel roller according to the present invention is directly addressed.

Indeed, said radial compression deforms the cylindrical rolling surface of the synchronized roller, which does not become exactly circular in that it has two flats. This radial compression of the rolling cylindrical surface induces to a certain extent a tangential compression of the material constituting said surface, which leads to a substantial change in the circumference of the synchronized roller. As a result, said tangential compression substantially alters the speed of rotation of the synchronized roller at the same linear speed of displacement of said roller.

To illustrate the consequences of the geometric alteration which has just been mentioned of said rolling cylindrical surface, let us take for example a synchronized roller which is placed between a fixed flat rolling surface and a moving flat rolling surface, each said surface being bordered. racks with which cooperate the pinions each integral with an end of said roller.

When moving the moving planar rolling surface, the synchronized roller moves half as fast as said surface relative to the fixed planar rolling surface and this, whatever the geometric alteration of the rolling cylindrical surface resulting from crushing under load of said roll.

However, concomitantly with the crushing of said synchronized roller, the angular displacement of the latter varies very substantially relative to its linear displacement.

The problem is that the angular displacement of the gears which are mounted at each end of said roller is determined by the teeth of said gears and by the teeth of the racks with which they cooperate. The angular displacement of said pinions is therefore invariable, while the angular displacement of the roller varies as a function of the radial load to which it is subjected.

Under heavy load, said roller tends to impose the gears attached to each of its ends a rotation speed different from that which the racks impose audits gears. As said roller is subjected to a high radial load, it adheres strongly to its running surfaces and resists the angular position correction that tend to produce its gears.

As a result, the teeth of the pinions and racks are subjected to an abnormal load which can lead to premature wear or even to the breaking of said teeth. In addition, said abnormal load produces friction, which is detrimental to the overall energy balance of the mechanism or apparatus in which the synchronized roll is implemented. It will be noted that the difference between the angular speed of the roller and that of the pinions can also come from the accuracy of the rolling cylindrical surface of the synchronized roller and from the precision of the system gear that constitute the pinions attached to each end of said roller and the racks with which they cooperate. Indeed, said precision not being infinite, the diameter of the rolling cylindrical surface does not exactly coincide with the diameter of the pitch circle of said gear system.

Also, in the case where, simultaneously, the synchronized roller is subjected to a high radial load while the teeth constituting said gear system are already in contact with each other and while the movement of said roller tends to bring said teeth closer to each other. each other, then, an abnormal load occurs at the level of said teeth which as previously can lead to premature wear or breakage. As before, said high radial load produces frictional energy losses that are harmful to the overall energy balance of the mechanism or apparatus in which the synchronized roll is implemented.

It will be noted in the patent No. FR 2 827 634 that the synchronized roller has in its middle a guide groove which cooperates with a vertical rib that has a running track integral with the engine block of the variable displacement motor. Said groove and said rib provide lateral guidance of the synchronized roll.

This configuration has the disadvantage of a certain complexity of implementation in particular because the runway integral with the engine block is no longer a single flat surface and easy to grind.

In addition, the division into two longitudinal portions of the rolling cylindrical surface of the synchronized roll doubles the number of edges of said surface. This involves making two bulges on said cylindrical surface - one by said portion - to limit the stress applied to the material constituting the cylindrical body of the synchronized roller at said edges, said stress being known to those skilled in the art under 'name of' edge effect '. It follows from this need for double convex that the two said longitudinal portions are subjected to a maximum Hertz pressure greater than that which would be subjected to a single rolling cylindrical surface not divided into two longitudinal portions. It will also be noted in Patent No. FR 2,827,634 that the synchronized roller is constituted by a one-piece assembly machined in one and the same piece of material while said roller cooperates with only three small racks and not four .

Note that two of said small racks are integral with the engine block while the integral transmission member of the piston of the variable displacement engine has only one.

This strategy makes it possible, on the one hand, to maintain the orientation of the synchronized roller with respect to the engine block while ensuring the proper synchronization of the vertical displacement of said roller relative to that of said piston and, on the other hand, to allow the member transmission to pivot without damage to said roll. If this strategy works effectively, it has the disadvantage of making it more complex and expensive to produce the synchronized roll.

Indeed, the rolling cylindrical surface of said roll as far as possible coincide with the diameter of the pitch circle of the gear system that form the pinions of said roller with the racks with which they cooperate, the realization of said gears becomes difficult in that it there is very little tool clearance to achieve said gears. Also, producing such a monoblock synchronized roll requires the use of expensive manufacturing methods such as precision electrochemical machining.

In addition, the surface treatments and heat treatments to be applied to the cylindrical rolling surface which is subjected to high Hertz pressures are not very compatible with the teeth of the gears which - being of small size - would become too fragile.

Consequently, it is necessary either to leave a large thickness of material at the level of said gears to remove the hard layer, for example case hardened or nitrided by machining, which greatly increases the cost of manufacturing the synchronized roll, or to hide during cementation of the synchronized roll. the areas where these gears must be made, which also leads to a cost price in manufacturing said high roll.

However, it should be noted that the unitary production cost of a monoblock synchronized roll as described above remains acceptable on a variable displacement motor as described in patent No. FR 2 827 634 because each cylinder of said engine does not has only one said roll.

On the other hand, the same unit cost would be unacceptable, for example in the case of producing the synchronized rolls of the central rotor bearings and the peripheral rotor bearings of the hydraulic motor-pump with fixed or variable displacement, as described in Patent No. FR 3. 001 774, given the large number of said rollers that includes said motor pump.

It is therefore to solve the functional and cost of manufacturing problems that have just been exposed that, according to a particular embodiment, the synchronized roller with freewheels:

Allows the speed of rotation of the rolling cylindrical surface that presents the central body of said roller is substantially different from that of the pinions that comprises said roll at its ends, and this, without subjecting the teeth of said pinions and racks with which they cooperate an abnormally high load especially when the synchronized roller is itself subjected to a high radial load;

Provides a cylindrical rolling surface that has the central body of said roller whose diameter is greater or smaller than that of the pitch circle of the gears that comprises said roll at its ends without affecting the proper operation of said roller, this potentially allowing to simplify and make it cheaper the manufacture of said roller and / or rolling tracks and racks or crowns with which it cooperates;

• allows - when said roller is subjected to a high radial load - a slight difference between the forward speed of the rolling cylindrical surface that has the central body of said roller and the forward speed of the gears that comprises said roll at its ends , and this, without subjecting the teeth of said gears and racks or crowns with which they cooperate with an abnormally high load;

Provides simple axial guide means, inexpensive to manufacture, and which do not require dividing the rolling cylindrical surface of said roll in several portions to make room for any guide groove; · Allows to entrust to dedicated and independent parts the rolling, meshing and axial guiding functions, which makes it possible to very significantly reduce the cost price in manufacturing said roller by resorting to productive manufacturing processes and at a low price of return for each said piece. It is understood that the synchronized freewheel roller according to the invention is mainly intended for large bearings, rotating at high speed, and subjected to heavy loads as presented in the patent relating to the hydraulic motor-pump with fixed displacement or variable published under No. FR 3,001,774 and belonging to the applicant. However, the synchronized freewheel roller according to the invention can also be applied without restriction to any other bearing or mechanism to which it would bring a functional, energetic, or of any nature whatsoever, said bearing or mechanism being implemented. in any application. By way of nonlimiting example, the synchronized freewheel roller according to the invention can be applied to the variable displacement motor, in particular the object of the patents FR 2 786 530 or FR 2 827 634, which belong to the applicant, by replacing the sleeve or monobloc rollers as described and disclosed in said patents. As another non-limiting example, the synchronized freewheel roller according to the invention may advantageously form the tangential arm antifriction roller as described in the patent relating to the hydraulic motor-pump with fixed or variable displacement published under the N ° FR 3 001 774 and belonging to the applicant. The other features of the present invention have been described in the description and in the dependent claims directly or indirectly dependent on the main claim.

The synchronized freewheel roller according to the present invention comprises a central body which exposes a rolling outer cylindrical surface provided between two rolling tracks on which it rolls simultaneously when said tracks move relative to each other, each said track being jointly lined with synchronizing racks or timing rings which form a gear system with a synchronization pinion present at each end of the central body, said roller comprising: · A smooth axis of diameter smaller than that of the cylindrical rolling surface, arranged at each terminating the central body, and around which the synchronization gear can rotate freely;

Axial pinion stop means integral with the smooth shaft which bear on the one hand, directly or indirectly on said axis and on the other hand, directly or indirectly on the synchronization pinion, to prevent said pinion from coming out the said axis;

Axial roller guide means which are supported on the one hand, directly or indirectly on the central body and on the other hand, directly or indirectly on at least one of the rolling tracks with which the rolling cylindrical surface cooperates, to keep the latter approximately centered on said tracks.

The synchronous freewheel roller according to the present invention comprises pinion axial stop means which consist of an elastic axial stop ring housed in an elastic ring groove arranged on the smooth axis.

The synchronized freewheel roller according to the present invention comprises axial roller guide means which consist of a rigid axial guide washer which is axially and directly or indirectly interposed between the synchronization pinion and an axial bearing surface which exposes the central body between the smooth axis and the outer cylindrical rolling surface, said rigid washer can bear on an axial guide track axially exposed at least one of the raceways. The synchronized freewheel roller according to the present invention comprises an axial guide spring washer which is interposed between the rigid axial guide washer and the synchronization gear, said spring washer tends to press on the one hand, the rigid axial guide washer. against the axial bearing surface with which it cooperates and secondly, the synchronization gear against the pinion axial stop means with which it cooperates.

The synchronized freewheel roller according to the present invention comprises an axial guide spring washer which is interposed between the synchronization pinion and the pinion axial stop means, said spring washer tending to press the synchronization pinion against the rigid washer of the pinion. axial guidance so that the latter is in turn pressed against the axial bearing face with which it cooperates.

The synchronized freewheel roller according to the present invention comprises an axial guide spring washer which comprises at its center centering claws snapped into a claw groove arranged on the smooth shaft, said groove constituting the axial pinion stop means. . The synchronized freewheel roller according to the present invention comprises elastic radial centering means which are interposed radially between the smooth axis and the synchronization gear, said means tending to always refocus said pinion on said axis. The synchronized freewheel roller according to the present invention comprises elastic radial centering means which consist of at least three radial radial centering tongues which on the one hand emerge radially from the inner surface of a central recess which the timing gear and secondly, can touch the smooth shaft.

The synchronized freewheel roller according to the present invention comprises elastic radial centering means which consist of at least one tongue washer which has in its center a rotating sleeve which can rotate about the smooth axis, and whose face outer cylindrical is bristled with at least three radial radial centering tongues that can press the inner surface of a central recess that includes the synchronization pinion.

The synchronized freewheel roller according to the present invention comprises elastic radial centering means which consist of at least three deformable rings which, on the one hand, are placed in a ring housing arranged on the inner surface of a recess central that includes the synchronization pinion and secondly, can touch the smooth axis.

The synchronized freewheel roller according to the present invention comprises elastic radial centering means which consist of at least one elastic washer with radial corrugations housed between on the one hand, the internal cylindrical face of a central recess that includes the pinion. synchronization and secondly, the smooth axis.

The synchronized freewheel roller according to the present invention comprises elastic radial centering means which consist of at least one compressible ring made of flexible material, said ring being inserted radially between, on the one hand, the internal surface of a obviously central that includes the synchronization pinion and secondly, a flexible ring support ring that can rotate around the smooth axis. The synchronized freewheel roller according to the present invention comprises a synchronization gear which has elastic radial centering means which tend to always refocus said pinion on the smooth axis and which consist of at least one radial radial centering tongue of which the first end is secured to a pinion rim that has the synchronization pinion at its periphery and whose second end is secured to a pinion hub that has the synchronization pinion at its center, said hub being articulated around the smooth axis.

The synchronized freewheel roller according to the present invention comprises a synchronization gear which has elastic radial centering means which tend to always refocus said pinion on the smooth axis and which consist of a thin web forming at least one sail cone, the first end of said sail being integral with a pinion rim that has the synchronization pinion at its periphery; while the second end of said web is secured to a pinion hub that has in its center the synchronization pinion, said hub being articulated around the smooth axis. The synchronized freewheel roller according to the present invention comprises in at least one end of the central body an edge-effect recess which is located between the smooth axis and the rolling outer cylindrical surface.

The following description with reference to the accompanying drawings and given by way of non-limiting example will better understand the invention, the features it has, and the benefits it is likely to provide:

Figures 1 and 2 are respectively a side view and a schematic sectional view of the synchronous roller freewheel according to the invention in a variant according to which the synchronization pinion has elastic radial centering means consisting of a thin web forming two sail cones while a rigid axial guide washer constitutes axial roller guide means, said rigid washer being held pressed against the axial bearing face with which it cooperates with an elastic guide washer axially interposed between said washer; rigid and synchronization gear.

3 is a three-dimensional view of the synchronized freewheel roll according to the invention and according to its variant shown in FIGS. 1 and 2. FIG. 4 is an exploded three-dimensional view of the synchronized freewheel roll according to the invention and according to its variant shown in FIG. Figures 1 and 2.

FIG. 5 is a three-dimensional view of a synchronized roller bearing using the synchronized freewheel roller according to the invention and according to its variant shown in FIGS. 1 and 2.

Figure 6 is an exploded three-dimensional view of the synchronized roller bearing shown in Figure 5, which implements the synchronized freewheel roller according to the invention and according to its variant shown in Figures 1 and 2.

Figures 7 and 8 are side views of the synchronized freewheel roller according to the invention and according to its variant shown in Figures 1 and 2, said views to illustrate

in the context of the synchronized roller bearing shown in FIGS. 5 and 6, the ability of said roller to accommodate any difference between the angular velocity along its own axis of its cylindrical external rolling surface on the one hand, and the speed also angularly along their own axis of its synchronization gears on the other hand, said difference leading to a rolling angular offset between said surface and said gears. Figures 9 and 10 are side views of the synchronous roller freewheel according to the invention and according to its variant shown in Figures 1 and 2, said views for illustrating

- in the context of the synchronized roller bearing shown in Figures 5 and 6 - the faculty said roller to accommodate any difference between the angular velocity of the rolling outer cylindrical surface relative to the axis of the bearing on the one hand, and the angular velocity of the synchronous gears always with respect to the axis of said bearing of on the other hand, said difference leading to a running eccentricity between said surface and said gears.

Figures 1 1 and 12 are schematic sectional views of the synchronized freewheel roller according to the invention and according to its variant shown in Figures 1 and 2, said views for illustrating - in the context of the synchronized roller bearing shown in Figures 5 and 6 - the ability of said roller to accommodate any rolling misalignment of its outer cylindrical rolling surface relative to the raceways with which it cooperates and this, in particular by means of the rigid axial guide washer and the washer axial guide elastic that comprises said roller. Figures 13 and 14 are respectively a side view and a schematic sectional view of the synchronous roller freewheel according to the invention in a variant according to which the synchronization pinion has elastic radial centering means consisting of a compressible ring made of material flexible while an elastic washer axial guide is interposed between the synchronization pinion and the pinion axial stop means, said washer having at its center centering claws snapped into a claw groove arranged on the smooth shaft, and while the terminations of the central body have an axial bearing face hollowed out of an anti-edge effect recess. Figure 15 is a schematic sectional view of the synchronization pinion and the smooth axis of the synchronized freewheel roller according to the invention in a variant according to which elastic radial centering means are interposed radially between said axis and said pinion which take the form of three radial radial centering tongues which emerge radially from the inner surface of a central recess that includes said pinion, said tabs being able to touch said axis.

Figure 16 is a schematic sectional view of the synchronization pinion and the smooth axis of the synchronized roller freewheel according to the invention in a variant according to which elastic radial centering means are interposed radially between said axis and said pinion which take in the form of a tongue washer which has in its center a rotating sleeve which can rotate about said axis, and whose outer cylindrical face is bristled with three radial radial centering tongues which can press on the inner surface of a central recess that includes the synchronization gear. Figure 17 is a schematic sectional view of the synchronization pinion and the smooth axis of the synchronized freewheel roller according to the invention in a variant in which elastic radial centering means are interposed radially between said axis and said pinion which take the form of three deformable rings each placed in a ring housing arranged on the inner surface of a central recess that includes the synchronization pinion, said rings being able to touch the smooth axis. Figure 18 is a schematic sectional view of the synchronization pinion and the smooth axis of the synchronized freewheel roller according to the invention in a variant according to which elastic radial centering means are interposed radially between said axis and said pinion which take the form of an elastic washer with radial corrugations housed between the inner cylindrical face of a central recess that includes the synchronization gear on the one hand, and the smooth axis on the other hand.

FIG. 19 is a schematic sectional view of the synchronization gear and the smooth axis of the synchronized freewheel roll according to the invention in a variant in which the synchronization gear has elastic radial centering means which consist of three tongues. radial centering elastics whose first end is secured to a pinion rim that has the synchronization pinion at its periphery, and whose second end is integral with a pinion hub that has said synchronization pinion at its center, said pinion hub articulating around the smooth axis.

DESCRIPTION OF THE INVENTION

FIGS. 1 to 19 show the synchronized freewheel roll 1, various details of its components, its variants, and its accessories.

As is particularly illustrated in FIG. 2, the synchronized freewheel roll 1 comprises a central body 2 which exposes a rolling outer cylindrical surface 3. As can be seen in FIGS. 7 to 12, said surface 3 is intended to be sandwiched between two rolling tracks 4 on which it rolls simultaneously when said tracks 4 move relative to each other.

In FIGS. 7 to 12 - and also in FIGS. 5 and 6, showing the synchronized roller with freewheels 1 according to the invention implemented in a synchronized roller bearing 35 - it will be noted that each running track 4 is integrally lined with synchronizing racks or synchronization rings 6 which form a gear system 7 with a synchronization pinion 8 present at each end 9 of the central body 2.

In FIGS. 1 to 19, it will be noted that the synchronized freewheel roll 1 according to the invention differs from the prior art in that it comprises a smooth axis 10 of smaller diameter than that of the rolling cylindrical surface 3, arranged at each end 9 of the central body 2, and around which the synchronization pinion 8 can rotate freely so that if the rolling tracks 4 tend to impose on the outer cylindrical rolling surface 3 a rotation speed substantially different from that which the synchronizing racks or synchronization rings 6 impose synchronization pinion 8, teeth 1 1 that includes the gear system 7 are not subjected to excessive load.

In addition, it will be noted - particularly in FIGS. 1 to 14 - that axial pinion stop means 12 integral with the smooth shaft 10 bear on the one hand, directly or indirectly on said axis 10, and on the other hand, directly or indirectly on the synchronization gear 8, to prevent said pinion 8 from coming out of said axis 10. Finally, it should be noted that the synchronized freewheel roll 1 according to the invention comprises axial roller guide means 13 which are supported on the one hand, directly or indirectly on the central body 2, and on the other hand, directly or indirectly on at least one of the rolling tracks 4 with which the rolling cylindrical surface 3 cooperates, to keep the latter approximately centered on said tracks 4. This is particularly evident in FIGS. 11 and 12.

FIGS. 1 to 4 show that the synchronized freewheel roll 1 according to the invention may comprise axial sprocket arresting means 12 which consist of an elastic axial stop ring 14 housed in a groove of FIG. elastic ring 15 arranged on the smooth shaft 10, an axial locking washer 25 being able in this case to be axially interposed between said ring 14 and the synchronization pinion 8.

In FIGS. 1 to 4 and 7 to 19, it should be noted that the axial roller guide means 13 may consist of a rigid axial guiding washer 16 which is axially and directly or indirectly interposed between the synchronization pinion 8 and a face axial support

17 that the central body 2 exposes between the smooth shaft 10 and the outer cylindrical rolling surface 3. In this case, said rigid washer 16 can bear on an axial guide track

18 that axially exposes at least one of the rolling tracks 4.

It will be noted that the rigid axial guide washer 16 and / or the axial guide track 18 can expose - at the level of the contact zone between said washer 16 and said track 18 - a rake edge 36 which prevents the material constituting said washer 16 narrows the constituent material of said track 18, or vice versa.

It may be specified here that - as illustrated in FIGS. 1, 4, 1 1 and 12 - an elastic axial guide washer 19 may be interposed between the rigid axial guiding washer 16 and the synchronization gear 8, said spring washer 19 tending to press on the one hand, the rigid axial guide washer 16 against the axial bearing surface 17 with which it cooperates and on the other hand, the synchronization gear 8 against the axial pinion stop means 12 with which he cooperates. As an alternative shown in FIGS. 13 and 14, an elastic axial guide washer 19 can be inserted between the synchronization pinion 8 and the pinion axial stop means 12, said spring washer 19 tending to press the synchronization pinion. 8 against the rigid axial guide washer 16 so that the latter is in turn pressed against the axial bearing face 17 with which it cooperates.

It will be noted that according to this particular configuration of the synchronized freewheel roll 1 according to the invention, said elastic washer 19 can be substituted for an axial locking washer 25 axially interposed between an elastic axial stop ring 14 housed in a groove. elastic ring 15 arranged on the smooth shaft 10 - said ring 14 constituting in this case the axial pinion stop means 12 - and the synchronization pinion 8. Still according to the particular configuration shown in FIGS. 13 and 14, it will be noted that the axial guide spring washer 19 may comprise at its center centering claws 37 snapped into a claw groove 38 provided on the smooth shaft 10, groove 38 then constituting the axial pinion stop means 12.

It will be noted in FIGS. 14 to 17 that elastic radial centering means 20 can be interposed radially between the smooth axis 10 and the synchronization pinion 8, said means tending to always refocus said pinion 8 on said axis 10, in particular after a radial force applied on said pinion 8 has eccentric said pinion 8 with respect to said axis 10.

It should be noted that according to this particular configuration of the synchronized freewheel roll 1 according to the invention, if for example the rolling outer cylindrical surface 3 is subjected to a high radial load and if the effective forward speed of said surface 3 with respect to the rolling tracks 4 with which it cooperates is substantially different from that of the synchronization pinion 8 with respect to said tracks 4, the elastic radial centering means 20 allow a slight eccentration of said pinion 8 with respect to the smooth axis 10 around which it can rotate, said eccentricity including avoiding that the difference in speed just mentioned is reflected in an excessive load of teeth 1 1 that includes the gear system 7.

According to the particular configuration of the synchronized freewheel roll 1 according to the invention 7 which has just been described, it can be seen in FIG. 15 that the radial centering elastic means

20 may consist of at least three radial radial centering tongues 21 which on the one hand emerge radially from the inner surface of a central recess 22 that the synchronization pinion 8 comprises and, on the other hand, can touch the smooth axle 10. It will be noted that the resilient centering tabs 21 may be made in the same piece of material as the synchronization pinion 8. As an alternative shown in FIG. 16, it will be noted that the radial centering elastic means 20 may consist of at least one tab washer 23 which has in its center a rotating sleeve 24 which can rotate about the smooth axis 10, and whose outer cylindrical face is bristled with at least three radial radial centering tongues

21 which can press on the inner surface of a central recess 22 that includes the synchronization pinion 8.

Another variant shown in FIG. 17 provides that the elastic radial centering means 20 may consist of at least three deformable rings 26 which, on the one hand, are placed in a ring housing 27 arranged on the inner surface of a obviously central 22 that includes the synchronization pinion 8 and secondly, can touch the smooth axis 10. It is noted that the deformable rings 26 can be mounted more or less tight between the ring housing 27 in which they are placed on the one hand, and the smooth axis 10 on the other hand. The variant shown in FIG. 18 for its part provides that the elastic radial centering means 20 may consist of at least one elastic washer with radial corrugations 32 housed between, on the one hand, the internal cylindrical face of a central recess 22 that comprises the synchronization gear 8 and secondly, the smooth axis 10, the central recess 22 may have a shape complementary to that of the elastic washer with radial corrugations 32. In Figure 14, it will be noted that the elastic means radial centering means 20 may also consist of at least one compressible ring 28 made of flexible material, said ring 28 being radially interposed between, on the one hand, the internal surface of a central recess 22 that the synchronization pinion 8 comprises. and on the other hand, a flexible ring support ring 29 which can rotate about the smooth axis 10.

Note that said flexible material may be an elastomer such as rubber, silicone, or any other compressible material having the desired elasticity and strength. It will also be noted that said flexible material can be overmolded directly on the synchronization pinion 8 and on the flexible ring support ring 29 so as to form with these components 8, 29 only one and the same piece.

FIG. 19 shows this time that it is the synchronization gear 8 itself which may have elastic radial centering means 20 which tend to always refocus said pinion 8 on the smooth axle 10 and which consist of at least a resilient radial centering tongue 21 whose first end is integral with a pinion rim 30 that has the synchronization pinion 8 at its periphery and whose second end is integral with a pinion hub 31 that is at its center timing pinion 8, said hub 31 articulating around the smooth axis 10.

Note that according to this particular configuration of the synchronized roller with freewheels 1 according to the invention, the radial radial centering tongue 21 can adopt any geometry without any limitation. However, the elastic radial centering tongue 21 is preferably of small thickness and oriented tangentially to the smooth axis 10 so as to provide a reserve of sufficient elasticity to allow the pinion rim 30 to be offset from the hub pinion 31, under the desired conditions.

As shown more particularly in FIGS. 1 to 4, the synchronization pinion 8 may have elastic radial centering means 20 which tend to always refocus said pinion 8 on the smooth shaft 10 and which consist of a thin web 33 forming at least one sail cone 34, the first end of said sail 33 being integral with a pinion rim 30 that has the synchronization pinion 8 at its periphery, while the second end of said sail 33 is integral with a hub gear 31 which has in its center the synchronization pinion 8, said hub 31 articulating around the smooth axis 10.

It should be noted that according to this particular configuration of the synchronized freewheel roller 1 according to the invention, the thin web 33 can be substituted for an axial guide spring washer 19 for pressing on the one hand and by means of the pinion rim 30, a rigid washer for axial guidance 16 against an axial bearing surface 17 exposed by the body central 2 between the smooth shaft 10 and the outer rolling cylindrical surface 3, and on the other hand, the pinion hub 31 against the axial pinion stop means 12.

It is also noted that advantageously, the thin veil 33 may be perforated to reduce rigidity.

Finally, FIG. 14 illustrates that at least one of the terminations 9 of the central body 2 may advantageously have an axial bearing face 17 situated between the smooth shaft 10 and the rolling outer cylindrical surface 3, said face 17 being hollowed out of an anti-edge effect recess 39.

Note that the edge-effect recess 39 in question may be for example of trunc toroidal shape, or be circular in a section "U", "V", or in any section whatsoever, or be of any hollow form that it is arranged in the axial bearing surface 17.

Thus, when the synchronized free wheel roller 1 supports a high load, the edge effect recess 39 limits the stress applied to the material constituting the central body 2 at the axial edges of the rolling outer cylindrical surface 3, said stress being known to those skilled in the art as the "edge effect".

In order to limit said stress, the edge-effect recess 39 provided as an alternative to the synchronized freewheel roll 1 according to the invention is advantageously substituted for a crown formed on the rolling outer cylindrical surface 3 or on the rolling tracks 4 with which it cooperates.

With respect to said crown, the edge-effect recess 39 has the advantage of producing a more homogeneous distribution of the contact pressure over the entire length of the rolling outer cylindrical surface 3.

The absence of a bulge also makes it possible to simplify the manufacture of the synchronized freewheel roll 1 according to the invention, the outer cylindrical rolling surface 3 then remaining perfectly cylindrical and not barrel-shaped. OPERATION OF THE INVENTION:

The operation of the synchronized roller with freewheels 1 according to the invention is easily understood from the view of FIGS. 1 to 19. To detail said operation, we will retain here the exemplary embodiment of the synchronized roller with freewheels 1 according to the invention as as illustrated in Figures 1 to 4, said roll 1 being identical in Figures 5 to 12, although less visible. Further, it will be assumed that said synchronized roll 1 is part of a synchronized roller bearing 35 such as that illustrated in FIGS. 5 and 6. It may be noted that said bearing 35 is similar to those found in the patent relating to a hydraulic motor-pump with fixed or variable displacement and published under No. FR 3,001,774, said patent belonging to the applicant. As shown in FIGS. 2 to 4, the synchronized freewheel roll 1 comprises a central body 2 which exposes a cylindrical outer rolling surface 3, which is sandwiched between two raceways 4 as shown in FIG. 5 and FIGS. 1 1, on which said surface 3 rolls simultaneously when said tracks 4 move relative to each other.

Each said track 4 is integrally lined with synchronization rings 6 which form a gear system 7 with a synchronization pinion 8 that presents each end 9 of the central body 2. For a better understanding of the operation of the synchronized roller with freewheels 1 according to the invention, the other synchronous rollers with freewheels 1 forming part of said bearing 35 are not represented in FIGS. 7 to 10, just as is represented only a portion of the synchronization rings 6 constituting said bearing 35, said portion being sufficient to illustrate said operation.

It can be seen in FIGS. 1 to 4 that the pinion axial stop means 12 consist of an elastic axial stop ring 14 housed in an elastic ring groove 15 which is arranged on the smooth axis 10 around which the synchronization pinion 8 can rotate freely, while an axial locking washer 25 is interposed axially between said ring 14 and said pinion 8.

FIGS. 1 to 4 are also shown here as exemplary embodiments of the synchronized freewheel roll 1 according to the invention that the axial roller guide means 13 consist of a rigid axial guide washer 16 which is axially interposed between the synchronization pinion 8 and the axial bearing face 17 exposed by the central body 2 between its smooth axis 10 and its rolling outer cylindrical surface 3.

Still according to this exemplary embodiment, it will be noted in FIGS. 2 and 4 that an elastic axial guide washer 19 is provided which is interposed between the rigid axial guide washer 16 and the synchronization pinion 8. Said elastic washer 19 tends to on the one hand, press the rigid axial guiding washer 16 against the axial bearing surface 17 and, on the other hand, the synchronization gear 8 against the axial pinion stop means 12.

It is particularly seen in Figures 1 1 and 12 that the rigid axial guide washer 16 is provided to bear if necessary on the axial guide track 18 that axially expose each of the rolling tracks 4. It is noted that the rigid washer of axial guidance 16 exposes - at the level of the contact zone between said washer 16 and said track 18 - a flank edge which prevents the material constituting said washer 16 from narrowing the material constituting said track 18. To illustrate the operation of the synchronized roller with freewheels 1 according to the invention, we will take the variant shown in Figures 1 to 4 according to which elastic radial centering means 20 are interposed radially between the smooth shaft 10 and the pinion of synchronization 8. Said means 20 tend to always refocus said pinion 8 on said axis 10, and here take the form of a thin web 33 forming two sail cones 34.

As can be seen clearly in FIG. 2, the first end of said web 33 is integral with a pinion rim 30 which is provided at its periphery with the synchronization pinion 8 while the second end of said web 33 is integral with a pinion hub. 31 that has in its center the synchronization pinion 8, said hub 31 articulating around the smooth axis 10.

We shall detail here what happens when the synchronized freewheel roll 1 according to the invention is loaded which - in a synchronized roller bearing 35 similar to those found in the patent No. FR 3,001,774 - intervenes only on approximately a half turn.

As a precaution, there will be sufficient clearance between the teeth 1 1 of the synchronization pinion 8 and those of the synchronization rings 6. The direction of rotation of the synchronized roller bearing 35 is not alternative but continuous, said game can result in any acoustic emission.

When on approximately one turn of the synchronized roller bearing the synchronized freewheel roller 1 is loaded, the latter is subjected to a high radial compression. As a result, said roll 1 crushes substantially to the point where its rolling outer cylindrical surface 3 is deformed, is no longer exactly circular, and has two flats. Said radial compression induces to a certain extent a tangential compression of the constituent material of the rolling outer cylindrical surface 3, which leads to a substantial change in the circumference of said surface 3.

In addition, there is an unavoidable difference between the initial diameter of the rolling outer cylindrical surface 3 and that of the pitch circle of the synchronization pinion 8 that each end 9 of the central body 2 of the synchronized freewheel roll 1 presents. This is due to the fact that the accuracy of realization of said surface 3 and said pinion 8 is not infinite. Whether it is the radial compression to which the outer cylindrical rolling surface 3 is subjected, or the difference between the initial diameter of said surface 3 and that of the pitch circle of the synchronization gears 8, these two factors lead - particularly when the synchronized roller with freewheels 1 moves under load relative to the rolling tracks 4 with which it co-operates - at a difference in angular velocity between that of the rolling outer cylindrical surface 3 and that of the synchronization gears 8. Note that said angular velocity here applies to the rotation of said surface 3 and said pinions 8 about the axis of the synchronized roller freewheel 1 to which they belong. If the synchronization gears 8 were rigidly integral with the central body 2, said difference in angular velocity would inevitably lead to an overload of the teeth 1 1 of the synchronization gear 8 and those of the synchronization rings 6.

As the synchronized freewheel roller 1 according to the invention provides that the synchronization gears 8 can freely rotate about the smooth axis 10 with which they cooperate, said difference in angular velocity does not have the effect of overloading the teeth 1 1, and the outer cylindrical rolling surface 3 can freely shift angularly with respect to the synchronization pinions 8. This offset is illustrated in FIGS. 7 and 8. FIG. 7 shows an initial angular offset DAI which is transformed after a certain distance traveled. by the synchronized freewheel roll 1 in a non-zero angular rolling offset DAR as shown in Figure 8. For better understanding, said DAR shift is visually voluntarily exaggerated.

It will be noted that the angular offset DAR operates without affecting the good maintenance of alignment and orientation of the synchronized roller with freewheels 1 relative to the raceways 4 with which it cooperates. In fact, the angular positions relating to the synchronized roller bearing 35 of the synchronization gears 8 of the same synchronized roller with freewheels 1 are invariably identical insofar as the two synchronization rings 6 of the same raceway 4 are identical. indexed in rotation in an identical manner. Said angular positions are therefore imposed by the gear system 7.

Furthermore, it is noted that if the rolling outer cylindrical surface 3 rolled without sliding on the raceways 4 with which it cooperates, its angular position relative to the synchronized roller bearing 35 would remain invariably identical to that of the two synchronized synchronized gears 8 to the same central body 2 that it, whatever the diameter of said surface 3.

At this stage of the explanation of the operation of the synchronized roller with freewheels 1 according to the invention, it is therefore understood that the only disturbance that could now overload the teeth 1 1 constituting the gear system 7 would be no longer a difference between the angular velocity of the rolling outer cylindrical surface 3 and that of the synchronization gears 8 along their own axis leading to an angular offset DAR as shown in FIG. 8, but of a difference between, on the one hand, the angular velocity of said surface 3 with respect to the synchronized roller bearing 35 and secondly, the angular speed of the synchronization gears 8 with respect to said bearing 35. This second difference can only come from manufacturing defects of the teeth 1 1 constituting the gear system 7. These defects necessarily exist because the accuracy of said embodiment is not infinite. It should be noted that said defects disturb the rotation of the synchronizing gears 8 with respect to the synchronized roller bearing 35. Consequently, said rotation can alternatively be moved slightly in advance to slightly late with respect to the ideal rotation of ideal synchronization gears 8. presenting a perfect involute profile.

In practice, said slight advance or said slight delay may be worth only a few microns. However, on teeth 1 1 of small size, said microns can represent high or even excessive load levels, which can lead to premature wear or even breakage of said teeth 1 January.

In addition, any abnormal overload of the teeth 1 1 produces friction, which is detrimental to the overall energy balance of the mechanism or device in which the synchronized roller bearing 35 is implemented. It is to prevent and to solve this problem that according to the embodiment of the synchronized roller with freewheels 1 according to the invention taken here to illustrate the operation, the synchronization pinion 8 that each terminal 9 of the central body 2 of said roll 1 comprises elastic centering means radial 20 which tend to always refocus said pinion 8 on the smooth axis 10 with which it cooperates. Said means 20 consist in this case of a thin web 33 forming two sail cones 34.

The rigidity of the two sail cones 34 has been predicted to be significantly lower than that of the teeth 1 1, but large enough to ensure a firm hold of the alignment of the central body 2 with respect to the rolling tracks 4.

The sequencing of the operation of the elastic radial centering means 20 is particularly illustrated by FIGS. 9 and 10. FIG. 9 shows an initial zero Exl eccentricity which is transformed after a certain distance traveled by the synchronized freewheel roll 1 into an eccentricity of ExR non-zero bearing as shown in Figure 10. For better understanding, said eccentricity ExR is visually voluntarily exaggerated.

It is therefore understood that, when fugally occurs a difference between the angular velocity of the rolling outer cylindrical surface 3 relative to the axis of the synchronized roller bearing 35 and the angular speed of the synchronization gears 8 with respect to the axis of said bearing 35, the pinion rim 30 that has at its periphery the synchronization pinion 8 is substantially offset relative to the pinion hub 31 that has in its center said pinion 8, which produces the ExR bearing eccentricity. This eccentricity ExR protects the teeth 1 1 from excessive overload, said teeth January 1 undergoing - consecutively to said eccentricity - a slight change in load.

It will be noted that once the outer cylindrical rolling surface 3 is relieved of any radial compression which occurs when the synchronized freewheel roll 1 is in the unloaded angular sector of the synchronized roller bearing 35, the elastic means of radial centering 20 can recenter the pinion rim 30 on the pinion hub 31 so as to find an initial eccentricity Exl zero as shown in Figure 9, before said surface 3 is subjected to a new charging cycle.

It has been noticed - particularly in FIGS. 1 to 4 - the axial roller guide means 13 which consist of a rigid axial guiding washer 16 axially interposed between the synchronization pinion 8 and the axial bearing face 17 which is exposed. the central body 2 between its smooth axis 10 and its rolling outer cylindrical surface 3.

It has also been noted in FIGS. 2 and 4 the elastic axial guide washer 19 which is interposed between the rigid axial guide washer 16 and the synchronization pinion 8. If, when under load, the rolling outer cylindrical surface 3 tends to to be misaligned with any one of the rolling tracks 4 with which it cooperates, the rigid axial guide washer 16 and the elastic axial guide washer 19 are provided to cooperate in maintaining said surface 3 aligned with said tracks 4 or at least realigning said surface 3 with said tracks 4 between two charging cycles of said surface 3.

The cooperative operation of said rigid washer 16 and said spring washer 19 is particularly illustrated in FIGS. 11 and 12.

FIG. 11 shows the axial position centered on the rolling tracks 4 which is sought for the rolling outer cylindrical surface 3. The initial misalignment D1 of said surface 3 with respect to said tracks 4 is therefore zero.

When the outer cylindrical rolling surface 3 is under load and if it tends to be misaligned with the rolling tracks 4, in a first step, the corresponding rigid axial guide washer 16 leaves said surface 3 to be misaligned by detaching from the face of the axial support 17 on which it is pressed, and compressing the elastic axial guide washer 19.

This results in a rolling misalignment DR of the rolling outer cylindrical surface 3 with respect to the rolling tracks 4 with which it cooperates non-zero, as shown in FIG. 12. For a better understanding, said misalignment DR is visually voluntarily exaggerated.

In a second step and as soon as the radial load exerted on the cylindrical external rolling surface 3 decreases or even disappears, the elastic axial guide washer 19 can reduce the said surface 3 to a lower force in a centered position with respect to the rolling tracks 4 and this, via the rigid axial guide washer 16. This results in a return to zero initial misalignment D1 of the outer rolling cylindrical surface 3 relative to the raceways 4 with which it cooperates, as shown in Figure 1 1. It is easily understood that the cooperation between the rigid axial guiding washer 16 and the elastic axial guiding washer 19 limits the pressure exerted by the rigid axial guiding washer 16 on the axial guiding track 18 that axially exposes the tread 4 with the fact that, in the absence of an axial guide spring washer 19, the rigid axial guide washer 16 should permanently refocus the rolling outer cylindrical surface 3, including when the latter is subjected to strong force. charge.

Moreover, the rigid axial guide washer 16 can hardly take up high axial forces because it cooperates with the axial guide tracks 18 via a small contact surface, said contact being necessarily largely slippery.

As a result of what has just been said, the synchronized roller bearing 35 of which the synchronized freewheel roller 1 according to this example is part is also not designed to take up a significantly high axial force, which should rather be taken for example by means of a ball or roller axial stopper known per se which cooperates with the synchronized roller bearing 35.

It will be noted that, in addition to the particular operation which has just been described and which gives it great durability and high energy efficiency, the synchronized freewheel roller 1 according to the invention makes it possible, in particular, to produce various devices, among which roller bearings. synchronized 35 very high energy efficiency, heavily loaded, and can rotate at high speed despite their large diameter. It will be noted that the synchronized freewheel roller 1 according to the invention is also intended to present the cost of manufacturing as low as possible.

Indeed, the synchronizing gears 8 of said roll 1 can be produced separately and at lower cost by sintering or cold stamping, without requiring high geometric precision or expensive profile corrections since the load applied to the teeth 1 1 constituting said gears 8 is weak.

The low load applied to synchronization gears 8 also makes it possible to avoid resorting for their manufacture to any expensive surface treatment or heat treatment.

The manufacture of simpler parts such as the rigid axial guide washer 16 or the elastic axial guide washer 19 does not in itself present any difficulty and is notoriously cheap. The manufacture of the central body 2 of the synchronized roller with freewheels 1 according to the invention also remains simple in particular that the realization of the smooth axis 10 does not call for high accuracy. Furthermore, the finishing of the outer cylindrical rolling surface 3 can be carried out by grinding known by the English name "centerless", which is notoriously precise, inexpensive, and guarantees excellent repeatability.

It will also be noted that to reduce the edge effect, a transverse crown may advantageously be formed on the rolling tracks 4 rather than on the rolling outer cylindrical surface 3.

The synchronization rings 6 may be provided attached by screwing to the mechanical parts which receive the synchronized roller bearing 35 while the rolling tracks 4 with which they cooperate are either directly made in said mechanical parts, or reported in the latter.

The possibilities of the synchronized freewheel roller 1 according to the invention are not limited to the applications which have just been described and it must also be understood that the foregoing description has been given only as a example and that it does not limit in any way the field of said invention which one would not go out by replacing the execution details described by any other equivalent.

Claims

Synchronized freewheel roll (1) comprising a central body (2) which exposes a rolling outer cylindrical surface (3) provided between two rolling tracks (4) on which it rolls simultaneously when said tracks (4) move on one relative to the other, each said track (4) being integrally lined with synchronization means (6) which form a gear system (7) with a synchronization gear (8) that each end (9) of central body (2), characterized in that it comprises:

• A smooth axis (10) of diameter less than that of the cylindrical rolling surface (3), arranged at each end (9) of the central body (2), and around which the synchronization pinion (8) can rotate freely;

Axial pinion stop means (12) integral with the smooth shaft (10) which are supported on the one hand, directly or indirectly on said axis (10) and on the other hand, directly or indirectly on the pinion synchronizing mechanism (8) for preventing said pinion (8) from coming out of said axis (10);

Axial roller guide means (13) which bear directly on the central body (2) directly or indirectly and directly or indirectly on at least one of the rolling tracks (4); ) with which cooperates the rolling cylindrical surface (3), to keep the latter approximately centered on said tracks (4).

Synchronized freewheel roll according to Claim 1, characterized in that the pinion axial stop means (12) consist of an elastic axial stop ring (14) housed in an elastic ring groove (15). arranged on the smooth shaft (10).

Synchronized freewheel roll according to Claim 1, characterized in that the axial roller guide means (13) consist of a rigid axial guide washer (16) which is axially and directly or indirectly interposed between the synchronization pinion (8) and an axial bearing surface (17) exposed by the central body (2) between the smooth shaft (10) and the cylindrical external rolling surface (3), said rigid washer (16) being able to bear on an axial guide track (18) axially exposed at least one of the rolling tracks (4).

Synchronized freewheel roll according to Claim 3, characterized in that an axial guide spring washer (19) is interposed between the rigid axial guide washer (16) and the synchronization gear (8), said spring washer (19). ) tending to press on the one hand, the rigid axial guide washer (16) against the axial bearing face (17) with which it cooperates and on the other hand, the synchronization pinion (8) against the means of axial pinion stop (12) with which it cooperates.

Synchronized freewheel roll according to Claim 3, characterized in that an axial guide spring washer (19) is interposed between the synchronization pinion (8) and the pinion axial stop means (12), said spring washer (19) tending to press the synchronizing pinion (8) against the rigid axial guide washer (16) so that the latter is in turn pressed against the axial bearing face (17) with which it cooperates. 6. synchronized roller freewheel according to claim 5, characterized in that the spring washer axial guide (19) has in its center centering claws (37) snapped into a claw groove (38) arranged on the axis smooth (10), said groove (38) constituting the axial pinion stop means (12). Synchronized freewheel roll according to Claim 1, characterized in that elastic radial centering means (20) are interposed radially between the smooth axis (10) and the synchronization gear (8), said means (20). tending to always refocus said pinion (8) on said axis (10). 8. synchronized roller freewheel according to claim 7, characterized in that the elastic radial centering means (20) consist of at least three radial radial centering tongues (21) which on the one hand emerge radially from the internal surface of a central recess (22) that includes the synchronization pinion (8) and secondly, can touch the smooth axis (10).

Synchronized freewheel roll according to Claim 7, characterized in that the elastic radial centering means (20) consist of at least one tongue washer (23) which has at its center a rotating sleeve (24) which can rotate around the smooth axis (10), and whose outer cylindrical face is bristled with at least three radial radial centering tongues (21) which can press on the inner surface of a central recess (22) that comprises the synchronization gear (8).

Synchronized freewheel roll according to Claim 7, characterized in that the elastic radial centering means (20) consist of at least three deformable rings (26) which, on the one hand, are placed in a housing. ring (27) arranged on the inner surface of a central recess (22) that includes the synchronization pinion (8) and on the other hand, can touch the smooth axis (10).

1 1. Synchronized freewheel roll according to Claim 7, characterized in that the elastic radial centering means (20) consist of at least one elastic washer with radial corrugations (32) housed between, on the one hand, the internal cylindrical face of a central recess (22) that includes the synchronization pinion (8) and secondly, the smooth shaft (10). Synchronized freewheel roll according to Claim 7, characterized in that the elastic radial centering means (20) consist of at least one compressible ring (28) made of flexible material, said ring (28) being interposed radially between on the one hand, the inner surface of a central recess (22) that comprises the synchronization pinion (8) and on the other hand, a flexible ring support ring (29) which can rotate around the smooth axis (10).

Synchronized freewheel roll according to Claim 1, characterized in that the synchronization pinion (8) has elastic radial centering means (20) which tend to always refocus said pinion (8) on the smooth axis (10). ) and which consist of at least one resilient radial centering tongue (21) whose first end is integral with a pinion rim (30) which has the synchronization pinion (8) at its periphery and whose second end is integral with a pinion hub (31) that has in its center the synchronization pinion (8), said hub (31) articulating around the smooth axis (10). 14. synchronized roller freewheel according to claim 1, characterized in that the synchronization pinion (8) has elastic radial centering means (20) which tend to always refocus said pinion (8) on the smooth shaft (10). ) and which consist of a thin web (33) forming at least one sail cone (34), the first end of said web (33) being integral with a pinion rim (30) which is present at its periphery the synchronization pinion (8) while the second end of said web (33) is integral with a pinion hub (31) which has at its center the synchronization pinion (8), said hub (31) articulating around of the smooth shaft (10). Synchronized freewheel roll according to Claim 1, characterized in that at least one of the ends (9) of the central body (2) has an edge-acting recess (39) between the smooth axis (10). and the outer cylindrical rolling surface (3).